// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#include "formats/gif/embedder.h"

#include <cstdint>
#include <optional>
#include <string>
#include <vector>

#include "absl/status/status_matchers.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "riegeli/bytes/string_reader.h"
#include "riegeli/bytes/string_writer.h"

namespace credentio {
namespace {

TEST(EmbedderTest, Write10BytePayload) {
  std::string image = "insert_@underscore";
  riegeli::StringReader<> input(image);

  std::string manifest_store = "0123456789";

  std::vector<uint8_t> expected_output = {
      'i', 'n', 's', 'e', 'r', 't', 0x21, 0xFF, 0x0B, 'C',  '2',
      'P', 'A', '_', 'G', 'I', 'F', 0x01, 0x00, 0x00, 0x0a, '0',
      '1', '2', '3', '4', '5', '6', '7',  '8',  '9',  0x00, '_',
      '@', 'u', 'n', 'd', 'e', 'r', 's',  'c',  'o',  'r',  'e',
  };
  std::string expected(expected_output.begin(), expected_output.end());

  std::string output_s;
  riegeli::StringWriter<> output(&output_s);

  GifEmbedder embedder;
  ABSL_ASSERT_OK(
      embedder.CopyAndEmbed(input, manifest_store, 6, std::nullopt, output));
  ASSERT_TRUE(output.Close());

  EXPECT_EQ(output_s, expected);
}

TEST(EmbedderTest, ReplaceExistingPayload) {
  std::string image = "before_OLD_C2PA_after";
  riegeli::StringReader<> input(image);

  std::string manifest_store = "0123456789";

  std::vector<uint8_t> expected_output = {
      'b', 'e', 'f', 'o', 'r', 'e',  '_',  0x21, 0xFF, 0x0B, 'C', '2', 'P',
      'A', '_', 'G', 'I', 'F', 0x01, 0x00, 0x00, 0x0a, '0',  '1', '2', '3',
      '4', '5', '6', '7', '8', '9',  0x00, 'a',  'f',  't',  'e', 'r',
  };
  std::string expected(expected_output.begin(), expected_output.end());

  std::string output_s;
  riegeli::StringWriter<> output(&output_s);

  GifEmbedder embedder;
  ABSL_ASSERT_OK(embedder.CopyAndEmbed(input, manifest_store, 7, 9, output));
  ASSERT_TRUE(output.Close());

  EXPECT_EQ(output_s, expected);
}

}  // namespace
}  // namespace credentio